i have 2 small (3") red pacus. i have them in a tank with 6 zebra danios.... they seem to get along great now but when i first put the zebras in the pacu chased one all around but couldnt catch him.... now they seem to just live together..... will they end up eating the danios?

I'm ready for the pressure.
The drama and the pleasure!If there is one thing I want to see here, it's HUMOR.I believe I can fly!
I believe I can touch the sky!
I think about it every night and day!I stand in awe of my body.

And they have been known to ram the sides of tanks and break them. When you get into the 300 gallon range, you're talking extra thick tempered glass which may, possibly, and I ain't going to be the one testing this and winding up with 300 gallons of water on my livingroom floor, prevent this.

Frankly, I think you're both right - 75 gallons per pacu sounds reasonable, but 300 gallons sounds like a good minimum size tank.